Circulatory System Nervous System The Human Body Digestive

Circulatory System Nervous System The Human Body Digestive System Respiratory System Sunshine State Standards Quiz Assignments

The Digestive System When you eat, your body digests. Acids and enzymes eat away at the surface of food to break it down. the food so your cells can use it to make energy. This energy helps us run and play.

The Digestive System Your Stomach Imagine being inside a big pink muscular bag -- sloshing back and forth in a sea of half-digested mush and being mixed with digestive chemicals. Acid rains down from the pink walls which drip with mucus to keep them from being eroded

The Digestive System Your Stomach Every time you think you've got your equilibrium back, the walls of muscle contract and fold in on themselves again. Over and over again, you get crushed under another wave of slop. Every wave mixes and churns the food and chemicals together more--breaking the food into even smaller and smaller bits. Then another valve opens. Is the end in sight you ask, as the slop gets pushed into the small intestine.

The Digestive System Inside the small intestine, chemicals and liquids from places like your kidneys and pancreas break down and mix up the leftovers. The small intestine looks like a strange underwater world filled with things that resemble small finger-like cactuses. But they're not cactuses, they're villi. Like sponges, they're able to absorb tremendous amounts of nutrients from the food you eat. From the villi, the nutrients will flow into your bloodstream.

The Digestive System Where Food Turns Into Poop Finally, the end of the large intestine is in sight! Now the drier leftovers are various handsome shades of brown. They sit, at the end of their journey, waiting for you to expel them -- out your anus. Of course, you know the rest! A glorious, if slightly stinky, journey, don't you think?

The Respiratory System Why do you need to breathe? All the cells in your body require oxygen. Without it, they couldn't move, build, reproduce, and turn food into energy. In fact, without oxygen, they and you would die! How do you get oxygen? From breathing in air which your blood circulates to all parts of the body.

The Respiratory System BREATH IN -- your body gets oxygen from the air. Rib muscles contract to pull ribs up and out. The DIAPHRAGM muscle contracts to pull down the lungs. Tissue expands to suck in air.

The Respiratory System BREATH OUT -- you get rid of other gases that your body does not need. Rib muscles relax. The Diaphragm muscle relaxes. Tissue returns to resting position and forces air out.

The Respiratory System Does it begin in the nose? Yup. About 20 times a minute, you breathe in. When you do, you inhale air and pass it through your nasal passages where the air is filtered, heated, moistened and enters the back of the throat. Interestingly enough, it's the esophagus or foodpipe which is located at the back of the throat and the windpipe for air which is located at the front. When we eat, a flap -- the epiglottis -- flops down to cover the windpipe so that food doesn't go down the windpipe. So -- back to breathing -- the air has a long journey to get to your lungs. It flows down through the windpipe, past the voice box or vocal cords, to where the lowermost ribs meet the center of your chest. There, your windpipe divides into two tubes which lead to the two lungs which fill most of your ribcage. Inside each of your sponge-like lungs, tubes, called bronchi, branch into even smaller tubes much like the branches of a tree. At the end of these tubes are millions of tiny bubbles or sacs called aleoli. Spread out flat, all the air sacs in the lungs of an adult would cover an area about the third of a tennis court.

Circulatory System What is it? It's a big name for one of the most important systems in the body. Made up of the heart, blood and blood vessels, the circulatory system is your body's delivery system. Blood moving from the heart, delivers oxygen and nutrients to every part of the body. On the return trip, the blood picks up waste products so that your body can get rid of them.

Circulatory System Your Heart About the size of your clenched fist, your heart is a muscle. It contracts and relaxes some 70 or so times a minute at rest - more if you are exercising -- and squeezes and pumps blood through its chambers to all parts of the body. And it does this through an extraordinary collection of blood vessels.

Circulatory System Your Blood Stream Your blood travels through a rubbery pipeline with many branches, both big and small. Strung together end to end, your blood vessels could circle the globe 2 1/2 times! The tubes that carry blood away from your heart are called arteries. They're hoses that carry blood pumped under high pressure to smaller and smaller branched tubes called capillaries. The tubes that more gently drain back to the heart are veins.

Circulatory System What's blood, anyway? Most of your blood is a colorless liquid called plasma. Red blood cells make the blood look red and deliver oxygen to the cells in the body and carry back waste gases in exchange. White blood cells are part of your body's defense against disease. Some attack and kill germs by gobbling them up; others by manufacturing chemical warfare agents that attack. Platelets are other cells that help your body repair itself after injury.

Nervous System What is the nervous system? Made up of your brain, your spinal cord, and an enormous network of nerves that thread throughout your body, it's the control center for your entire body. Your brain uses information it receives from your nerves to coordinate all of your actions and reactions. Without it, you couldn't exist!

Nervous System What are nerves? They're thin threads of nerve cells, called neurons that run throughout your body. Bundled together, they carry messages back and forth just the way that telephone wires do. Sensory nerves send messages to the brain and generally connect to the brain through the spinal cord inside your backbone. Motor nerves carry messages back from the brain to all the muscles and glands in your body.

Nervous System So how do they pass along messages? Through the marvels of chemistry and a kind of electricity! Neurons are thin. Some are very small, and some can be three feet long! All are shaped somewhat like flat stars which have, to varying degrees, been pulled at each end so that they have long fingers. The fingers of one neuron almost reach to the next neuron.

Nervous System When a neuron is stimulated -- by heat, cold, touch, sound vibrations or some other message -- it begins to actually generate a tiny electrical pulse. This electricity and chemical change travels the full length of the neuron. But when it gets to the end of finger-like points at the end of the neuron, it needs help getting across to the next extended finger. That's where chemicals come in. The electrical pulse in the cells triggers the release of chemicals that carry the pulse to the next cell. And so on and so on.

Quiz Time How many times per minute do you breath? a) 15 b) 30 c) 20 d) 10

Your Correct!!! We do breath 20 times per minute. Assignment

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Today's Activities Word Search Scrabble Visit this website for fun facts about the human body

Sunshine State Standards 3 rd Grade Processes of Life The student describes patterns of structure and function in living things Knows that human body is made of different systems with structures and functions that are related.